Abstract:

The antioxidant and cytoprotective capacities of E-resveratrol and Z-resveratrol werecompared using chemical and cellular assays. Chemical assays revealed that the twoisomerswere dose-dependently active in●O2ˉ-scavenging,ferric reducing antioxidant power (FRAP),Cu(2+)-reducing antioxidant capacity(CUPRAC),2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl3-oxide radical(PTIO●)-scavenging(pH 7.4 and pH 4.5), and 1,1-diphenyl-2-picryl-hydrazyl(DPPH●)-scavenging assays.Thecellular assay indicated that the two isomers could also increasecell viabilities. However, quantitative analyses suggested that E-resveratrol exhibited stronger effectsthan Z-resveratrol in all chemical and cellular assays. Finally, the conformations of E-resveratroland Z-resveratrol were analyzed. It can be concluded that both E-resveratrol and Z-resveratrolcan promote redox-related pathways to exhibit antioxidant action and consequently protect bonemarrow-derived mesenchymal stem cells (bmMSCs) from oxidative damage. These pathwaysinclude electron transfer (ET) and H(+)-transfer, and likely include hydrogen atom transfer (HAT).The E-configuration, however, improves antioxidant and cytoprotective capacities of resveratrols.The detrimental effect of the Z-configuration may be attributed to the non-planar preferentialconformation, where two dihedral angles block the extension of the conjugative system.